|Canine Epilepsy Project seeks dog DNA via the Web|
By Kate Dalke
March 15, 2002
The search for epilepsy genes in dogs starts on the Internet. A Web site asking dog owners to send researchers DNA samples from epileptic dogs has generated thousands of responses and even some friendly competition among dog owners. In less than three years, the Canine Epilepsy Project has collected about 3,500 blood samples from more than 70 breeds of dogs.
The goal of the project is to identify the genes involved in inherited forms of epilepsy. The disease, which is characterized by repeated seizures, can result from brain damage due to a head injury or tumor. Epilepsy can also run in families, and the researchers aim to identify genetic risk factors by tracking the inheritance of the disease in dog families.
The project includes researchers from the University of Missouri in Columbia, the University of Minnesota in St. Paul, Ohio State University in Columbus, and the Animal Health Trust in Suffolk, U.K. The researchers share data and credit for discoveries made using the database.
One of the project's findings to date is that male dogs are in fact at greater risk for epilepsy than females. Previous studies have reported a difference in the frequency of disease between the sexes. The project now says that male predominance for epilepsy is the case for most breeds and particularly true for some breeds. Male Irish Setters and Standard Schnauzers are three times more likely to have epilepsy than their female counterparts.
From the start, the success of the project has depended on having samples from families of epileptic dogs. The researchers catalogue the DNA samples and decide which ones to study based on the completeness of an individual dog's family tree. Most samples have come from purebred dogs, which tend to have more detailed family histories than mixed breeds because of the records breeders keep. Purebred dogs are also more at risk for epilepsy than other dogs because inbreeding tends to perpetuate genetic diseases.
The project Web site provides information about canine epilepsy and how to treat the disease, which affects about two to six percent of the dog population. The site tells owners how to collect a DNA sample on their next trip to the veterinarian.
The site also keeps a running tally of the number of DNA samples received for each breed. This has created a kind of horse race between the breeding clubs, notes Dennis O'Brien of the Veterinary School at the University of Missouri. Breed clubs compete to provide more information and samples from their specific breeds. This is great for research, adds O'Brien.
The project's goals sometimes differ for participants and researchers. Pet owners and breeders hope the research will lead to the development of a DNA test that could determine if a dog is a carrier of epilepsy-associated genes. This would allow breeders to someday 'breed-out' epilepsy. The researchers want to help the dogs but also realize that identifying genes responsible for canine epilepsy may lead to a better understanding of epilepsy in humans and other species.
Canine epilepsy research lags behind similar studies in humans in part because the map of the dog genome is incomplete, says O'Brien. A more complete dog map will help researchers identify genes involved in the disease.
For more information visit Canine Epilepsy Network
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